Expressing bacterial bioluminescence in human cell lines: Engineering autobioluminescent reporter cells to screen for endocrine disruptor chemicals Project Summary This Small Business Innovation Research Phase II project proposes to build upon our successful Phase I demonstration of autonomous endocrine disruptor chemical (EDC) detection using human cell lines to engineer a novel Tier 1 screening assay for the low cost, high-throughput detection of estrogenically- and androgenically-active compounds across multiple human tissue types to address the National Institute of Environmental Health Sciences (NIEHS) request for Improved Test Systems for Prioritization and Safety Evaluation. Current Tier 1 EDC screening approaches require the use of non-human cell lines that can obscure bioavailability data, employ radioactive materials that require dedicated use areas and specially trained personnel, or rely upon the use of expensive analytical equipment that prevents high-throughput testing. Furthermore, following this initial Tier 1 screen, those chemicals that putatively express endocrine disrupting activities must still be screened against Tier 2 animal models to validate the results. Currently, there are over 500 contract testing service companies in the U.S. alone that perform Tier 1 style assays for the chemical, pesticide, and personal care products industries at an average cost of $1,000 per assay. However, as the number of potential EDCs requiring testing expands, and with many states now adopting legislation to begin screening all municipal water supplies for EDCs, market growth within this sector is expected to increase at an annual rate of 13.5% to approach $36 billion by 2016, clearly demonstrating the need for new assays that can reduce screening costs, increase screening throughput, and provide more relevant human bioavailability data without necessitating the use of animal models. The EDC-responsive, substrate-free, autobioluminescent reporter cell lines developed by 490 BioTech under our Phase I efforts demonstrated the ability to detect EDCs similarly to existing Tier 1 screening assays while employing a human cell culture-based model that significantly reduced the cost and personnel effort of testing while simultaneously providing an uninterrupted stream of visual data over the lifetime of the reporter cell as it interacted with and reacted to EDC treatment. In this proposal, we will leverage this technology to develop fully self-contained, human cell-based, high- throughput screening assays that provide more accurate and realistic information in regards to EDC bioavailability and effects on human health. With application of these assays reducing the cost of Tier 1 EDC screening over 100-fold to less than $10 per compound, we believe we possess a product capable of significantly impacting the EDC screening market and advancing our understanding of novel compound endocrine disruptor activity as it pertains to public health and consumer safety.